🛡️ Nameserver Resilience

Domains whose DNS hangs on a single nameserver, address, network or AS · all insights

DNS should never hang on one server. This page counts the .dk domains whose nameservers share a single host, address, network or autonomous system, the single points of failure that turn one outage into a dead domain. Data comes from our own scanners, which re-resolve every .dk domain in the zone roughly once a week.

🛡️ Single points of failure

1,182,584 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1490.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3040.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6830.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,07664.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,2097.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-03 04:10).

📋 One autonomous system

757,076 domains
DomainNameservers and addresses
a-rengoering.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-rep.dkbill.ns.cloudflare.com 108.162.193.74 AS13335, 172.64.33.74 AS13335, 173.245.59.74 AS13335, 2606:4700:58::adf5:3b4a AS13335, 2803:f800:50::6ca2:c14a AS13335, 2a06:98c1:50::ac40:214a AS13335
lina.ns.cloudflare.com 108.162.192.187 AS13335, 172.64.32.187 AS13335, 173.245.58.187 AS13335, 2606:4700:50::adf5:3abb AS13335, 2803:f800:50::6ca2:c0bb AS13335, 2a06:98c1:50::ac40:20bb AS13335
a-resultat.dkkinsley.ns.cloudflare.com 108.162.194.75 AS13335, 162.159.38.75 AS13335, 172.64.34.75 AS13335, 2606:4700:50::a29f:264b AS13335, 2803:f800:50::6ca2:c24b AS13335, 2a06:98c1:50::ac40:224b AS13335
salvador.ns.cloudflare.com 108.162.195.100 AS13335, 162.159.44.100 AS13335, 172.64.35.100 AS13335, 2606:4700:58::a29f:2c64 AS13335, 2803:f800:50::6ca2:c364 AS13335, 2a06:98c1:50::ac40:2364 AS13335
a-rolskov.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.curanet.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
a-round.dkbuck.ns.cloudflare.com 108.162.193.78 AS13335, 172.64.33.78 AS13335, 173.245.59.78 AS13335, 2606:4700:58::adf5:3b4e AS13335, 2803:f800:50::6ca2:c14e AS13335, 2a06:98c1:50::ac40:214e AS13335
cloe.ns.cloudflare.com 108.162.192.86 AS13335, 172.64.32.86 AS13335, 173.245.58.86 AS13335, 2606:4700:50::adf5:3a56 AS13335, 2803:f800:50::6ca2:c056 AS13335, 2a06:98c1:50::ac40:2056 AS13335
a-roundtest.dkbuck.ns.cloudflare.com 108.162.193.78 AS13335, 172.64.33.78 AS13335, 173.245.59.78 AS13335, 2606:4700:58::adf5:3b4e AS13335, 2803:f800:50::6ca2:c14e AS13335, 2a06:98c1:50::ac40:214e AS13335
cloe.ns.cloudflare.com 108.162.192.86 AS13335, 172.64.32.86 AS13335, 173.245.58.86 AS13335, 2606:4700:50::adf5:3a56 AS13335, 2803:f800:50::6ca2:c056 AS13335, 2a06:98c1:50::ac40:2056 AS13335
a-s-a-p.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-s-c.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-s-e.dkns3.nordicway.dk 2a01:4f8:c2c:d3c0::1 AS24940, 78.47.45.64 AS24940
ns4.nordicway.dk 2a01:4f8:c010:24a2::1 AS24940, 78.47.56.84 AS24940
a-s-service.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
a-samfund.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-sbh.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
a-scenen.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-scheutz.dkmina.ns.cloudflare.com 108.162.194.251 AS13335, 162.159.38.251 AS13335, 172.64.34.251 AS13335, 2606:4700:50::a29f:26fb AS13335, 2803:f800:50::6ca2:c2fb AS13335, 2a06:98c1:50::ac40:22fb AS13335
osmar.ns.cloudflare.com 108.162.195.124 AS13335, 162.159.44.124 AS13335, 172.64.35.124 AS13335, 2606:4700:58::a29f:2c7c AS13335, 2803:f800:50::6ca2:c37c AS13335, 2a06:98c1:50::ac40:237c AS13335
a-schou.dkns3.nordicway.dk 2a01:4f8:c2c:d3c0::1 AS24940, 78.47.45.64 AS24940
ns4.nordicway.dk 2a01:4f8:c010:24a2::1 AS24940, 78.47.56.84 AS24940
a-schultz.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-serve.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
a-set.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-sh.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
a-shop.dkns1.azehosting.net 2a01:4f8:13b:3146::1 AS24940, 94.130.138.185 AS24940
ns2.azehosting.net 2a01:4f8:c17:5f0a::2 AS24940, 88.99.15.5 AS24940
ns3.azehosting.net 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
a-sign.dkns1.123hotel.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.123hotel.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
a-site.dkachiel.ns.cloudflare.com 108.162.195.123 AS13335, 162.159.44.123 AS13335, 172.64.35.123 AS13335, 2606:4700:58::a29f:2c7b AS13335, 2803:f800:50::6ca2:c37b AS13335, 2a06:98c1:50::ac40:237b AS13335
nola.ns.cloudflare.com 108.162.192.212 AS13335, 172.64.32.212 AS13335, 173.245.58.212 AS13335, 2606:4700:50::adf5:3ad4 AS13335, 2803:f800:50::6ca2:c0d4 AS13335, 2a06:98c1:50::ac40:20d4 AS13335
a-skadeservice.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-skaelskoer.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
a-skat.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-skilte.dkashton.ns.cloudflare.com 108.162.195.173 AS13335, 162.159.44.173 AS13335, 172.64.35.173 AS13335, 2606:4700:58::a29f:2cad AS13335, 2803:f800:50::6ca2:c3ad AS13335, 2a06:98c1:50::ac40:23ad AS13335
vida.ns.cloudflare.com 108.162.192.236 AS13335, 172.64.32.236 AS13335, 173.245.58.236 AS13335, 2606:4700:50::adf5:3aec AS13335, 2803:f800:50::6ca2:c0ec AS13335, 2a06:98c1:50::ac40:20ec AS13335
a-skovtrold.dkns1.sommerhusteknik.dk 188.245.107.110 AS24940, 2a01:4f8:c0c:18fd::1 AS24940
ns2.sommerhusteknik.dk 2a01:4f8:c013:11a::1 AS24940, 91.107.223.151 AS24940
a-skrot.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-soemod.dkruth.ns.cloudflare.com 108.162.192.143 AS13335, 172.64.32.143 AS13335, 173.245.58.143 AS13335, 2606:4700:50::adf5:3a8f AS13335, 2803:f800:50::6ca2:c08f AS13335, 2a06:98c1:50::ac40:208f AS13335
todd.ns.cloudflare.com 108.162.193.146 AS13335, 172.64.33.146 AS13335, 173.245.59.146 AS13335, 2606:4700:58::adf5:3b92 AS13335, 2803:f800:50::6ca2:c192 AS13335, 2a06:98c1:50::ac40:2192 AS13335
a-soerensen.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-sol.dkdale.ns.cloudflare.com 108.162.193.95 AS13335, 172.64.33.95 AS13335, 173.245.59.95 AS13335, 2606:4700:58::adf5:3b5f AS13335, 2803:f800:50::6ca2:c15f AS13335, 2a06:98c1:50::ac40:215f AS13335
lilith.ns.cloudflare.com 108.162.194.143 AS13335, 162.159.38.143 AS13335, 172.64.34.143 AS13335, 2606:4700:50::a29f:268f AS13335, 2803:f800:50::6ca2:c28f AS13335, 2a06:98c1:50::ac40:228f AS13335
a-sonniksen.dkns3.nordicway.dk 2a01:4f8:c2c:d3c0::1 AS24940, 78.47.45.64 AS24940
ns4.nordicway.dk 2a01:4f8:c010:24a2::1 AS24940, 78.47.56.84 AS24940
a-sorensen.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-soroe.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-sound.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-speakers.dkken.ns.cloudflare.com 108.162.193.127 AS13335, 172.64.33.127 AS13335, 173.245.59.127 AS13335, 2606:4700:58::adf5:3b7f AS13335, 2803:f800:50::6ca2:c17f AS13335, 2a06:98c1:50::ac40:217f AS13335
lily.ns.cloudflare.com 108.162.192.130 AS13335, 172.64.32.130 AS13335, 173.245.58.130 AS13335, 2606:4700:50::adf5:3a82 AS13335, 2803:f800:50::6ca2:c082 AS13335, 2a06:98c1:50::ac40:2082 AS13335
a-spendos.dkns1.linode.com 2600:14c0:6::2 AS21342
ns2.linode.com 2600:14c0:6::3 AS21342
ns3.linode.com 2600:14c0:7::3 AS21342, 92.123.95.3 AS21342
ns4.linode.com 2600:14c0:7::4 AS21342, 92.123.95.4 AS21342
ns5.linode.com 2600:14c0:7::2 AS21342, 92.123.95.2 AS21342
a-sport.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.curanet.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
a-ss.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-staldrens.dkkenia.ns.cloudflare.com 108.162.194.93 AS13335, 162.159.38.93 AS13335, 172.64.34.93 AS13335, 2606:4700:50::a29f:265d AS13335, 2803:f800:50::6ca2:c25d AS13335, 2a06:98c1:50::ac40:225d AS13335
wesley.ns.cloudflare.com 108.162.193.246 AS13335, 172.64.33.246 AS13335, 173.245.59.246 AS13335, 2606:4700:58::adf5:3bf6 AS13335, 2803:f800:50::6ca2:c1f6 AS13335, 2a06:98c1:50::ac40:21f6 AS13335
a-stars.dkns1.eurodns.com 199.167.66.107 AS23393, 2610:1c8:b002::107 AS23393
ns2.eurodns.com 104.37.178.107 AS23393, 2610:1c8:b001::107 AS23393
ns3.eurodns.com 199.167.66.108 AS23393, 2610:1c8:b002::108 AS23393
ns4.eurodns.com 104.37.178.108 AS23393, 2610:1c8:b001::108 AS23393
a-steinicke.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
a-storage.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-store.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
a-storm.dkns1.dnsserver.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.dnsserver.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
a-supply.dkluciana.ns.cloudflare.com 108.162.194.131 AS13335, 162.159.38.131 AS13335, 172.64.34.131 AS13335, 2606:4700:50::a29f:2683 AS13335, 2803:f800:50::6ca2:c283 AS13335, 2a06:98c1:50::ac40:2283 AS13335
ricardo.ns.cloudflare.com 108.162.195.211 AS13335, 162.159.44.211 AS13335, 172.64.35.211 AS13335, 2606:4700:58::a29f:2cd3 AS13335, 2803:f800:50::6ca2:c3d3 AS13335, 2a06:98c1:50::ac40:23d3 AS13335
a-support.dkdonald.ns.cloudflare.com 108.162.193.158 AS13335, 172.64.33.158 AS13335, 173.245.59.158 AS13335, 2606:4700:58::adf5:3b9e AS13335, 2803:f800:50::6ca2:c19e AS13335, 2a06:98c1:50::ac40:219e AS13335
meera.ns.cloudflare.com 108.162.192.195 AS13335, 172.64.32.195 AS13335, 173.245.58.195 AS13335, 2606:4700:50::adf5:3ac3 AS13335, 2803:f800:50::6ca2:c0c3 AS13335, 2a06:98c1:50::ac40:20c3 AS13335
a-surel.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
a-system.dkmatt.ns.cloudflare.com 108.162.193.131 AS13335, 172.64.33.131 AS13335, 173.245.59.131 AS13335, 2606:4700:58::adf5:3b83 AS13335, 2803:f800:50::6ca2:c183 AS13335, 2a06:98c1:50::ac40:2183 AS13335
melina.ns.cloudflare.com 108.162.194.184 AS13335, 162.159.38.184 AS13335, 172.64.34.184 AS13335, 2606:4700:50::a29f:26b8 AS13335, 2803:f800:50::6ca2:c2b8 AS13335, 2a06:98c1:50::ac40:22b8 AS13335
a-sælle-honne.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
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